Pg boosted VSMCs proliferation and intimal hyperplasia, and the expression of vascular cell proliferative phenotypic markers S100 calcium-binding protein A9 (S100A9) and embryonic isoform of smooth muscle myosin heavy chain (SMemb) was observed higher on the surface of VSMCs of Pg-infected mice and in aneurysm specimens from Pg-infected patients [101,102]. This evidence concerns the gene S100A9 and aneurysm.